Does umbilical cord bilirubin level has predictive value in pathologic neonatal hyperbilirubinemia?

The increase in the use of breast feeding and the decrease in mother's hospitalization in the past few years have caused an increase in the infant bilirubin level, so it is necessary to introduce methods which can identify infants with higher risks of hyperbiliru binemia. The aim of this study is to determine the predictive value of measuring the umbilical cord bilirubin for pathologic hyperbilirubinemia, that is the bilirubin more than 15mg /dl. This prospective study was performed from November 2009 to December 2010 on the umbilical cord serum of 274 newborns who were born in Iran-Mashhad Razavi Hospital. The neonates’ Apgar scores were above 7, weights more than 2.5 kg and gestational ages above 37 weeks. Once again their bilirubin level was measured via skin during the third to fifth day. Using the Smirnov test,, one-sample Kolmogorov test, t-test, and Man Whitney test, we analyzed the data. P< 0.05 was considered significant. Out of 274 newborns, 178 cases were followed up. Ninety-three infants of the monitored cases had hyperbilirubinemia (total bilirubin ≥ 15 mg/dl or group A, 85 of the infants did not have pathologic hyperbilirubinmia (total bilirubin < 15 mg/dl or group B). The average umbilical cord bilirubin for group A was 2.32 ± 0.78 mg/dl, and for group B was 1.98 ± 0.72 mg/dl; so statistically, there is a significant difference. At the cut-off point of 2 mg/dl for umbilical cord bilirubin, sensitivity was obtained to be 68.86% and the specificity was obtained to be 61.18%. If the amount of bilirubin in the umbilical cord is more than 2 mg/dl, it can be considered as a contributing factor among other risk factors in the prediction of the infant’s pathologic hyperbilirubinemia.